From long-expected new products like the Samsung Galaxy S6 and HTC One M9 to surprises like the Huawei Watch and HTC Vive, here's everything you missed on the day before the Mobile World Congress officially opened.

The Korean electronics giant's low-power DDR4 memory chips, due to ship in 2014, will help lift a key performance bottleneck in today's mobile devices. Samsung says the new chips are faster and use less power, too.